Semi-High Throughput Screening for Potential Drought-tolerance in Lettuce (Lactuca sativa) Germplasm Collections.

This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of the world.

The role of NDR1 in pathogen perception and plant defense signaling.

The biochemical and cellular function of NDR1 in plant immunity and defense signaling has long remained elusive. Herein, we describe a novel role for NDR1 in both pathogen perception and plant defense signaling, elucidated by exploring a broader, physiological role for NDR1 in general stress responses and cell wall adhesion. Based on our predictive homology modeling, coupled with a structure-function approach, we found that NDR1 shares a striking similarity to mammalian integrins, well-characterized for their role in mediating the interaction between the extracellular matrix and stress signaling.

Arabidopsis NDR1 is an integrin-like protein with a role in fluid loss and plasma membrane-cell wall adhesion.

Arabidopsis (Arabidopsis thaliana) NON-RACE-SPECIFIC DISEASE RESISTANCE1 (NDR1), a plasma membrane-localized protein, plays an essential role in resistance mediated by the coiled-coil-nucleotide-binding site-leucine-rich repeat class of resistance (R) proteins, which includes RESISTANCE TO PSEUDOMONAS SYRINGAE2 (RPS2), RESISTANCE TO PSEUDOMONAS SYRINGAE PV MACULICOLA1, and RPS5. Infection with Pseudomonas syringae pv tomato DC3000 expressing the bacterial effector proteins AvrRpt2, AvrB, and AvrPphB activates resistance by the aforementioned R proteins. Whereas the genetic requirement for NDR1 in plant disease resistance signaling has been detailed, our study focuses on determining a global, physiological role for NDR1.

From perception to activation: the molecular-genetic and biochemical landscape of disease resistance signaling in plants.

More than 60 years ago, H.H. Flor proposed the "Gene-for-Gene" hypothesis, which described the genetic relationship between host plants and pathogens.

Premature leaf senescence modulated by the Arabidopsis PHYTOALEXIN DEFICIENT4 gene is associated with defense against the phloem-feeding green peach aphid.

Aphids, which are phloem-feeding insects, cause extensive loss of plant productivity and are vectors of plant viruses. Aphid feeding causes changes in resource allocation in the host, resulting in an increase in flow of nutrients to the insect-infested tissue. We hypothesized that leaf senescence, which is involved in the programmed degradation of cellular components and the export of nutrients out of the senescing leaf, could be utilized by plants to limit aphid growth.